Electronic speech synthesizers have recently become available which are both low enough in cost and small enough in size for many applications. The uses of these speech synthesizers have included entertainment, educational and communication applications.
Different means have been used to input the information to control the speech synthesizer. However, these devices have lacked the capability to selectively and directly control information that will be inputted to the speech synthesizer. Some of the prior art devices are really no more than phonographs, with the control information being imprinted on a record-type device already encoded with audibletype control information. These devices not only fail to incorporate use of a speech synthesizer but also fail to provide a means to directly and selectively control the control information on an incremental level by a user. Other devices, such as conventional record players and tape recorders have failed for much the same reasons. Still other devices have required a person who, in addition to being intimately familiar with the phonetic structure of a language, is able to operate a phonetic keyboard at the rate of about 120 word per minute in order to produce speech at a normal speaking rate.
In the entertainment and educational area, a device manufactured by Texas Instruments known as the SPEAK & SPELL.TM. learning aid produces canned speeches in response to keyboard manipulations and in accordance with various computer controlled games or exercises. Such a device lacks the facility to input control data at a high enough speed such that the synthesizer will output audible speech information at a normal speech rate. Also, the speech information so produced is of a canned variety. Another commercial product in the entertainment and educational area is a toy for children in which a phonographic-type record accompanies each page of a book and is imprinted on the page itself. A record player-type device is overlayed on top of the page and in this way operates much like a conventional record player, although the record remains stationary and the record player pickup device moves and is overlayed on top of the record instead of the record being overlayed on top of the record player. However, with this device, although a person can associate pictures on the page with a text, there is no direct association between the sounds produced and the text segments, since the information on the record can be accessed only in its entirety, and cannot be selectively accessed in smaller segments. In this way, it is similar to a phonograph record in that it does not lend the user the capability to selectively access smaller segments of the particular material.
In the communication area, language translating computers have recently become available on the market. Such devices provide a keyboard having one key for each letter of the alphabet. A user types in, letter by letter, a word of one language and an electronic display will display the word and its foreign equivalent in text form. Speech synthesizers have recently been combined with such devices to provide an audible rendition of the foreign language equivalent. Clearly however, a rate of communication still depends on the typing rate of the operator, which is very limited since the information must be inputted letter by letter.
Thus, the prior art devices have failed to provide apparatus for controlling speech synthesizers so that data can be put in on an incremental basis with a manual apparatus controlled by the user, but which still provides the capacity for information to be inputted to the speech synthesizer at a high enough rate of speed so that the speech so produced is at a normal speech rate of about 120 words a minute.
There is a need for a device which could provide selective manual control of input data to a speech synthesizer which is capable of inputting data both at phonemic increments and at a mormal speed rate. This would facilitate the learning of written and spoken native languages by children and foreign languages by people of all ages.